Currently, Office is available for iOS and Android smartphone users, either of which must have a subscription to Office 365. It is unclear whether a similar requirement will be necessary on a touch version of Office for the iPad. And while we've seen leaks before hinting that an iPad version of Office was coming, this time the information about a touch-first version is coming from Microsoft's top executive.
Among the information that is still unknown about the touch-first edition of Office, is when we might see it launched by Microsoft. Redmond's head of applications and services, Qi Lu, said that the company is working on touch-first versions of the suite's core apps and that the plan is to "bring these apps to Windows devices, and also to other devices in ways that meet out customers' needs."
source:TheVerge via BGR